1. Technical Field
This invention generally relates to radio receivers and more specifically relates to radio receivers for digital satellite radio.
2. Background Art
For many decades, radio has been an important part of life in the United States, providing countless hours of news, entertainment, and music. Radio receivers typically receive radio signals from local radio stations that transmit their signal over an assigned frequency at or below a prescribed power level. Due to the power limitations imposed on radio transmissions, the range of a radio station is very limited. When a person gets into a vehicle to drive a long distance and tunes to a radio station, the reception on that radio station will typically degrade within an hour or two, forcing the driver to seek a new radio station. There are many wide expanses in the United States that have few people, and hence few (if any) radio stations to choose from. This can become very annoying to a driver that wants to hear news, a sporting contest, a talk radio program, or music while driving.
Recently, two different companies have proposed implementing satellite radio systems that will allow a user to choose from 100 or so radio channels that are all available anywhere within the continental United States. XM Satellite Radio of Washington and CD Radio Inc. of New York are the two companies that have obtained licenses from the Federal Communications Commission (FCC) to broadcast digital radio signals via satellite. Broadcasting CD-quality music from a satellite is not new. DirectTV offers many music-only channels that may be listened to via a television or home theater system that is coupled to a digital satellite dish that is approximately 46 cm (18 inches) across. This system, however, requires a stationary satellite dish pointed at a fixed-position satellite to receive the digital music transmissions, making the system unworkable for car radios. Even if a driver were to somehow mount a satellite dish to a vehicle, the orientation of the dish would be constantly changing, and could therefore not receive music channels from existing fixed position satellites.
The systems implemented by XM Satellite Radio and by CD Radio, Inc. both use multiple satellites to transmit signals that can be received by small car-phone sized antennas. This allows these satellite radio signals to be received by both stationary receivers (such as a radio receiver in a home stereo system) and mobile receivers (such as a radio receiver in a car). The age of digital satellite radio is close at hand. For a small monthly fee of around $10, a subscriber can enjoy up to 100 channels of digital music and other radio programming, many of which do not have any commercials.
One feature of satellite radio is that the artist and song title (or program name/description) are transmitted along with the programming. This allows a satellite radio receiver to display the current channel, as well as the programming being played on the current channel. However, there is currently no way to display any information on a digital radio receiver regarding what is playing on other channels. The prior art requires that a user manually tune to another channel and listen to the program being played to determine if the user wants to remain tuned to that channel. If information regarding other channels were available on the radio display, the user could then decide whether to switch channels if a more favorable program is playing on a different channel. Without a way for a user to tell what is playing on other channels, users will be forced to manually scan channels until a desired program is heard.